Shinjitsu Nishimura

Distinctive flow pattern of wall shear stress and oscillatory shear index: similarity and dissimilarity in ruptured and unruptured cerebral aneurysm blebs

OBJECT The difference in the hemodynamics of wall shear stress (WSS) and oscillatory shear index (OSI) between ruptured and unruptured aneurysms is not well understood. The authors investigated the hemodynamic similarities and dissimilarities in ruptured and thin-walled unruptured aneurysm blebs. METHODS Magnetic resonance imaging-based fluid dynamics analysis was used to calculate WSS and OSI, and hemodynamic and intraoperative findings were compared. The authors also compared ruptured and unruptured thin-walled blebs for the magnitude of WSS and OSI. RESULTS Intraoperatively, 13 ruptured and 139 thin-walled unruptured aneurysm blebs were identified. Twelve of the ruptured (92.3%) and 124 of the unruptured blebs (89.2%) manifested low WSS and high OSI. The degree of WSS was significantly lower in ruptured (0.49 ± 0.12 Pa) than in unruptured (0.64 ± 0.15 Pa; p < 0.01) blebs. CONCLUSIONS Ruptured and unruptured blebs shared a distinctive pattern of low WSS and high OSI. The degree of WSS at the rupture site was significantly lower than in the unruptured thin-walled blebs.

Efficacy of middle meningeal artery embolization in the treatment of refractory chronic subdural hematoma

Background: There are no established treatment procedures for repeatedly recurring chronic subdural hematoma (CSH). In this study, we discussed the efficacy of middle meningeal artery (MMA) embolization in preventing recurrence of CSH. Methods: We performed superselective angiography of MMA in four patients who suffered from repeated recurrence of CSH. After angiography, we performed embolization of MMA with endovascular procedure. Results: In all cases, superselective angiography of MMA revealed diffuse abnormal vascular stains that seemed to represent the macrocapillaries in the outer membrane of CSH. In all the patients, there were no recurrences or enlargements of CSH after the embolization of the MMA. Conclusion: MMA embolization can be an effective adjuvant procedure in preventing the recurrence of CSH.

Postpartum dissecting aneurysm of the posterior cerebral artery

Intracranial dissecting aneurysm may cause subarachnoid hemorrhage (SAH) or infarction, and postpartum dissecting aneurysm is rare. A 30-year-old 6 days postpartum woman presented with posterior cerebral artery (PCA) dissection evolving dramatically over a short period. She had been well until 6 days after delivery when she suffered sudden onset of headache, vomiting, and unconsciousness. CT scan demonstrated SAH and digital subtraction angiography (DSA) revealed a fusiform dilatation of the left PCA (P3/P4 segment). The initial diagnosis was ruptured dissecting aneurysm, and conservative management was recommended in the acute period. DSA showed smoothening of the vascular wall 6 days after onset, and obliteration of the left P3/P4 segment was observed 13 days after onset. She was discharged without neurological deficits 26 days after onset. Postpartum SAH due to dissecting aneurysm of the PCA is rare, but should be considered in the differential diagnosis of postpartum headache.

Cranial hemophilic pseudotumor associated with factor IX deficiency: case report

BACKGROUND Hemophilic pseudotumor is an unusual complication occurring in only 1% to 2% of patients with severe factor VIII or IX deficiency, and manifests as a progressive enlargement of hematoma by recurrent hemorrhage, often resulting in bone destruction or resorption due to the chronic pressure of osseous hemorrhage. Cranial hemophilic pseudotumors are extremely rare, with only 4 previous cases associated with mild or moderate factor XIII deficiency. CASE DESCRIPTION A 24-year-old man with moderate deficiency of factor IX developed a cranial pseudotumor as a swelling in the frontal scalp. Blood coagulation profile revealed extended activated partial thromboplastin time (58.2 seconds). Factor IX analysis showed 3% of normal activity. Computed tomography and magnetic resonance imaging demonstrated an extra-axial lesion with bone destruction, enhanced rim, and signal changes consistent with chronic hemorrhage. Surgical removal was performed. Histologic examination disclosed old blood coagulum. CONCLUSIONS This case of cranial hemophilic pseudotumor in a patient with moderate factor IX deficiency suggests that cranial pseudotumor should be considered in the differential diagnosis of cranial lesion in a patient with hemophilia, and adequate replacement therapy in the perioperative period is essential to achieve safe surgical removal.

Clinical Manifestations, Character of Aneurysms, and Surgical Results for Unruptured Cerebral Aneurysms Presenting with Ophthalmic Symptoms

OBJECTS Cases with unruptured cerebral aneurysms presenting with visual symptoms were investigated about their site, size, symptom, operative methods and results. MATERIAL Between 1984 and 1999, 8 cases were treated in Sendai National Hospital. One man and 7 women, mean age 66.4 years. Ophthalmic symptoms were as follows: diplopia in 6, visual acuity deterioration in 2, impaired visual field in 2 and ptosis in 3. Aneurysm location was IC cavernous in 3, IC ophthalmic in 3, ICPC in 1 and Acom in 1. Aneurysms of more than 25 mm numbered 6 cases. RESULTS Operative methods and results were as follows: Direct clipping 3 cases, parent artery occlusion + EC/IC bypass 4 cases, Aneurysm trapping + EC/IC bypass 1 case. One patient who underwent direct clipping died following intraoperative complication. Of the remaining 7 cases, visual symptoms were improved in 4, remained unchanged in 2 cases, worsened in 1 case. CONCLUSIONS These results suggest that in cases with unruptured large or giant aneurysms presenting with ophthalmic symptoms, especially in IC cavernous or IC ophthalmic aneurysms, parent artery occlusion + EC/IC bypass is the safest operative procedure.

Ectopic recurrence of dysplastic gangliocytoma of the cerebellum (Lhermitte–Duclos disease): a case report

Lhermitte–Duclos disease is a rare clinical entity characterized by slow deformation of the cerebellar lesion. A 53-year-old woman presented with Lherimitte–Duclos disease manifesting as ataxic gait, occipital headache, and loss of consciousness. Magnetic resonance imaging demonstrated striated and laminar pattern lesions in the right cerebellar hemisphere and vermis. She underwent subtotal removal of the vermis compressing the brainstem, but the cerebellar hemisphere appeared normal and was preserved. Histological findings were consistent with Lherimitte–Duclos disease. Two years later, magnetic resonance imaging revealed enlargement of the right hemispheric lesion. Intraoperative appearance of the hemisphere demonstrated marked enlargement of the folia. Subtotal removal was performed. Histological examination showed no malignant findings. Lhermitte–Duclos disease may recur, and should be carefully followed up as a low-grade neoplasm, not as a hamartomatous disorder.

Subarachnoid hemorrhage after an ischemic attack due to a bacterial middle cerebral artery dissecting aneurysm: case report and literature review.

A 78-year-old woman suffered sudden-onset left hemiparesis. There were no remarkable infectious findings. Computed tomography (CT) demonstrated a low-intensity area supplied by the right middle cerebral artery (MCA). The diagnosis was cerebral ischemia and she was conservatively treated with hyperosmotic fluids. Two days after the ischemic stroke she suddenly became comatose. CT showed diffuse subarachnoid hemorrhage (SAH) in the basal cistern associated with a right intra-Sylvian and a right frontal subcortical hematoma. Three-dimensional (3D)-CT angiography demonstrated occlusion of the M2 portion of the right MCA. Four days after the ischemic onset she died of brain herniation. Autopsy revealed arterial dissection in the intermediate membrane of the right MCA bifurcation and occlusion of the M2 portion of the thrombosed right MCA. Gram staining showed remarkable bacterial infection in the thrombus. SAH after an ischemic attack due to MCA dissection is extremely rare. We suspect that bacterial infection was involved in the formation of her fragile dissecting aneurysm.

Cerebral venous thrombosis with dural arteriovenous fistulas and antiphospholipid syndrome: a case report

Dear Editor, Dural arteriovenous fistulas (DAVF) and antiphospholipid syndrome (APS) are important risk factors for cerebral venous thrombosis (CTV). We describe a young patient presenting with CVT with DAVF and APS. However, the combination of the DAVF and APS has not been reported in patients with CVT. A 38-year-old man visited our outpatient clinic because of abnormal behavior. He had no mental retardation. Two weeks before the visit, he drove into a closed ski slope and crashed his car. When he was found, he had been in the car for 2 days in the ski slope. He was confused and then transferred to a local hospital. Examinations including head CT scan showed no abnormality. His daily behavior initially appeared to be normal after the episode. However, he began to demonstrate abnormal activities such as pouring water onto salad and became unable to do easy arithmetic. He did not complain of headache and fever. He showed no nuchal rigidity on admission. He was disoriented and had bradyphrenia. Mini-mental state examination was 22/30 in which he had severe loss of recent memory. The Rey–Osterrieth figure test revealed severe verbal and visual memory deficits along with inattention. He had no abnormality in cranial nerves. D-dimer was normal and b2GPI-dependent IgG antiphospholipid antibody was 54 U/ml (\3.5 U/ml). Brain MRI revealed abnormal high signals in the bilateral thalamus (Fig. 1). Brain MR venography (MRV) revealed thrombosis in the straight sinus. Digital subtraction angiography showed DAVF from marginal tentorial arteries of bilateral internal carotid arteries, bilateral occipital arteries, tentorial branches of bilateral median meningeal arteries, and right lateral posterior choroidal artery. These DAVF flowed into the vein of Galen, and the blood flow of the DAVF regurgitated into bilateral internal cerebral veins. The vein of Galen and the straight sinus were occluded. The patient was diagnosed as CVT with multiple DAVF and APS. Anticoagulant therapy was started from the day of admission, but he fell into stupor. Three times of transarterial embolisation (TAE) were performed on the DAVF and then the DAVF was surgically resected. The specimen showed arteriovenous shunting between dural arteries and veins with multilayered elastic tissue in venous walls. After the operation, attention and verbal memory on the Rey–Osterrieth figure test remarkably improved. A followup brain MRI showed a decrease in the area of abnormal intensity (Fig. 1). He was discharged without aid. We described a patient with CVT, in which cognitive disorder was a prominent symptom due to venous infarction of the bilateral thalamus by the occlusion of the straight sinus. The patient had DAVF draining into the vein of Galen. Additionally APS was found in our patient. APS is also one of the major risk factors of CVT [1]. DAVF and CVT have been closely related to each other. However, it remains to be elucidated whether DAVF is the Y. Miki (&) M. Tomiyama A. Arai T. Kimura C. Suzuki J. Nunomura M. Baba Department of Neurology, Aomori Prefectural Central Hospital, Higashi Tsukurimichi 2-1-1, Aomori, Japan e-mail: yasuomiki@hotmail.com

Sylvian Aqueduct Syndrome and Parkinsonism in Aqueduct Stenosis: Improvement in Global Rostral Midbrain Dysfunction Associated With Resolution of Abnormal Hyperintensity on MRI

Objective and Importance:Sylvian aqueduct syndrome (SAS) is associated with a complex clinical picture, which suggests global rostral midbrain dysfunction. Clinical Presentation:A 34-year-old woman developed SAS and Parkinsonism secondary to aqueductal stenosis and was treated by endoscopic third ventriculostomy (ETV) as an initial treatment, which led to the successful resolution of the symptoms. At admission, she exhibited only memory disturbance, slight cognitive impairment and urinary incontinence after recent childbirth. Magnetic resonance imaging (MRI) revealed aqueductal stenosis with the enlargement of the third and lateral ventricle with normal sized fourth ventricle. Several days later, the patient displayed upward gaze paralysis (Parinaud’s syndrome), Parkinsonian hands tremor, and somnolent confusional state. An MRI revealed abnormal intensity in the midbrain and upper pons as well as bulging of the posterior portion of the third ventricle. The dramatic resolution of the patient’s Parinaud’s syndrome, Parkinsonian tremor, and drowsy state after ETV was accompanied by the disappearance of the abnormal intensity in the midbrain and posterior bulging of the third ventricle. This characteristic change, which occurred simultaneously in both the clinical and MRI findings, revealed the lesion responsible for the SAS and Parkinsonism. A drastic change in the ventricular size or transtentorial pressure gradient might have also caused distortion and stretching of the midbrain. Conclusions:The simultaneous resolution of the clinical symptoms and abnormal MRI findings after ETV revealed the lesion responsible for this patient’s SAS and Parkinsonism. Early ETV allowed the reversal of the SAS and Parkinsonism and should be considered as the first-line treatment.

Clinical analysis of dural arteriovenous fistulas

[背景]硬膜動静脈瘻(dural AVF)は多彩な臨床像を呈する血管奇形である.[対象・方法]過去6年間に経験した頭蓋内duralAVFの画像所見・臨床症状・治療法・治療成績を検討した.[結果]全28例(男性14例,女性14例,平均年齢63.5歳).病変部位は海綿静脈洞部13例,横-S状静脈洞部7例,前頭蓋底部4例,辺縁静脈洞部1例,頭蓋頚椎移行部3例,Bor-den分類ではtypeI18例,typeII8例,typeIII2例,I18例中5例(28%)が無症候性,7例(39%)が慢性な経過,II8例中5例(63%)が急激な頭蓋内圧亢進症状を呈し,出血発症2例はIIとIIIであった.治療方法はdrainer clipping術4例,direct sinus packing2例,血管内塞栓術12例,放射線治療2例,経過観察8例.転帰は18例で症状の改善が得られ,9例で症状は不変,1例はくも膜下出血で死亡であった.[結語]個々の臨床症状や血管撮影のパターンに応じた的確な治療で良好な経過が得られる.